Ultrastable and ultrafast MXene derived TiO₂ with rGO constrained 3D network for efficient capacitive deionization

To address the bottlenecks of poor electrode material stability and insufficient ability to remove organic pollutants, this study constructed a super-stable, ultra-fast ion-transporting MXene-derived TiO₂-rGO three-dimensional network CDI electrode material (denoted as MXene/TiO₂-rGO) through an in situ growth strategy. Ti₃C₂T_x MXene and rGO can both constrain the agglomeration of TiO₂, ensuring uniform distribution of TiO₂ and improving the conductivity of the material. At the same time, the 3D network structure can effectively alleviate the self-stacking of Ti₃C₂T_x MXene and enhance the structural stability of MXene/TiO₂-rGO. Therefore, MXene/TiO₂-rGO electrode shows outstanding desalination performance, with a maximum salt adsorption rate of 11.24 mg g⁻¹ min⁻¹ and a desalination capacity of 34.98 mg g⁻¹ in HCDI system. After 100 cycles, the capacity retention rate remains at 80 %. Besides, MXene/TiO₂-rGO demonstrates good photocatalytic performance, and under xenon lamp irradiation, it can effectively degrade sulfamethoxazole in synergy with PMS. MXene/TiO₂-rGO, as a stable three-dimensional network structure CDI electrode material, has demonstrated dual functions of efficient desalination stability and rapid pollutant degradation in the field of CDI water treatment.